Inércia Sensorial

PHP named parameters with default values

Comments 30 de December, 2005 sob PHP.
Tags:

I got a comment by Adam Kramer, whose blog I linked on the original article about PHP named parameters, saying that would be cool to have a mix of default and named parameters.

So I made a nice cup of coffe and a few hacks later, came up with a way to do it, and went to tell Adam. Well, sadly his Wordpress broke my HTML text (just like mine will probably do it too), so I am posting it here.

It uses a weirdness like $named->default_var($default_var), but it works For PHP5 only... with previous versions of PHP, every parameter would need to have its own function inside the named classes. Doable, but definitively undesirable

PLAIN TEXT

PHP:

class named
{
public function clean()
{
foreach ($this as $key => $value) {
unset($this->$key);
}
}
private function __call($method, $arguments)
{
if (isset($this->$method)) {
return $this->$method;
} else {
return $arguments[0];
}
}
}
$named = new named();
function inputText($name, $maxlength = 5)
{
global $named;
$html = "<input type=\"text\" name=\"$name\" ";
$html .= "maxlength=\"" . $named->maxlength($maxlength) . "\" ";
$html .= " />\n";
$named->clean();
return $html;
}
echo inputText('input_name');
echo inputText('input_name', $named->maxlength = 10);
/*
Outputs:
<input type="text" name="input_name" maxlength="5" />
<input type="text" name="input_name" maxlength="10" />
*/

But Adam also said that passing named parameters with "=" is easier (and I agree). On my third cup of coffe, this is what I wrote:

PLAIN TEXT

PHP:

class named
{
private $x = array();
public function clean()
{
foreach ($this as $key => $value) {
unset($this->$key);
}
}
private function __set($nm, $val)
{
$this->x[$nm] = $val;
}
private function __get($nm)
{
global $$nm;
if (isset($$nm)) {
return $$nm;
} else {
return $this->x[$nm];
}
}
}
class form extends named
{
function inputText($name)
{
$this->maxlength = 5;
$this->size = 10;
$html = "<input type=\"text\" name=\"$name\" ";
$html .= "maxlength=\"" . $this->maxlength . "\" ";
$html .= "size=\"" . $this->size . "\" ";
$html .= " />\n";
$this->clean();
return $html;
}
}
$form = new form();
echo $form->inputText('input_name');
echo $form->inputText('input_name', $size = 20);
/*
Outputs:
<input type="text" name="input_name" maxlength="5" size="10" />
<input type="text" name="input_name" maxlength="5" size="20" />
*/

$this->maxlength = 5; and $this->size = 10; are used to set the default function "parameters". They can't go inside the parenthesis because otherwise the global keyword can't access it.